Quantity   Component name
1 × Raspberry Pi Octoprint required for GPIO toggling to power printer on/off.
1 × 1N4001 Diode For relay flyback protection.
1 × Omron G5NB-1A-E Relay Chosen for 12V coil voltage, low coil current and 5A switching current at 28VDC.
1 × 2N7000G MOSFET Just had these lying around. No specific reason.
1 × 3-Pin terminal block For connecting to the 12V of the printer/power supply.
1 × 2-Pin 0.1" Headers For connecting to the Raspberry Pi's GPIO
1 × 10k Resistor For pull-down on the MOSFET gate.
1 × Wires for Raspberry Pi/Printer power supply
1 × Perfboard For constructing the circuit on.